Now go to tunnel details, where you will see all the parameters for successful tunnel creation and allocated IPv6 address block. As we have two separate lan segments we will need /48 address block, allocate it by clicking on "allocate".

At this point router should be capable of reaching any IPv6 destination.

Lan segment address blocks

Next, we need to assign a subnet address from the /48 address block to two of our ethernet segments. Since the prefix length for IPv6 subnet is always /64, we have 65536 subnets available from /48 address block! Let's just assign 2001:470:dcd9:1::/64 to Lan1, and 2001:470:dcd9:2::/64 to Lan2.

Notice, that advertise flag is enabled. It means that Stateless auto configuration is enabled and absolutely no address configuration is required on client side.

Routing between segments

We will use OSPF as the routing protocol between both routers. Notice that in IPv6 network additional addresses between routers are not required. Link-local addresses are used for connectivity between routers.

When configuring OSPF on a network without configured IPv4, important configuration part is to set up router-id. Wen this parameter is not set, OSPF will try to get it from configured IPv4 addresses, if IPv4 address are missing process will fail and OSPF will not work.

At this point both LAN segments can reach Ipv6 Global network routed over 6to4 tunnel.